Field of the Invention
This invention relates to a power generation apparatus, and in particular, but without limitation, to a power generation apparatus adapted to convert a reciprocating mechanical input into electrical power.
Description of the Related Technology
Mechanical-electrical power generators are well known and have been available for many years, the most common type being a dynamo, which converts a rotational mechanical input into electrical power. A dynamo comprises a rotor provided with electrical coils, which is arranged to rotate within a magnetic stator whereby the relative movement of the coils and magnets induces an electrical current in the coils, which can be drawn from the dynamo via brushes which make contact with the coil or coils at certain rotational positions. The efficiency of dynamo-type generators has, in recent times, increased, thereby providing a relatively efficient means to generate power using a rotating mechanical input. In many cases, the rotational mechanical input can be provided by a turbine, which is driven by the movement of a fluid, such as, say, steam in a power station, or the wind in the case of a wind turbine generator.
Unfortunately, the overall efficiency of a dynamo-type power generation system, that is to say, the combination of turbine and generator, can be significantly reduced by the efficiency of the turbine, or the turbine-generator coupling. For example, the efficiency of a wind turbine generator is largely limited by the efficiency of the turbine blades, which convert the substantially linear movement of the wind into a rotational output. Moreover, wind turbines generally rotate at speeds which are too slow for the generator, in which case a gearbox needs to be provided, which steps-up the output speed of the turbine to an acceptably high input speed at the generator input. Mechanical losses in the gearbox can lead to significant efficiency losses in the system overall.
In these respects, some work has been carried out previously to develop linear power generation devices that operate by tilting a track upon which a magnetic rotor is adapted to roll. In these devices, as rotor rolls along the track, it passes by a number of pickup coils in which an electric current is induced by the movement of the rotor's magnets relative to the coil. The rotor can be arranged to move in several ways, but in all cases, the rotor is caused to roll along the track by tilting the track.